Control of volatiles in electrode paste
The control items of electrode paste include fixed carbon, volatile, ash and water. Generally, the four items can be calculated by analyzing the volatile, ash and water. Volatile matter shall be controlled within a certain range, otherwise the following results will be caused.
1. If the volatiles are too high, the following adverse results will be caused:
1 it is not easy to sinter, with poor strength and easy to break.
2. Large shrinkage and poor strength, and hard fracture may occur.
3 fast oxidation and fast consumption of electrode paste.
4. It is easy to be layered and sintered into special shape. Besides the difficulty of lowering the electrode, it is also easy to be broken.
5. When discharging the electrode, the load is reduced much and the load is increased slowly, which affects the output.
2. If the volatile is too low, the following adverse results will be caused:
1 premature sintering, poor strength and easy hard fracture.
2. The adhesion is not enough, the strength is poor, and it is easy to break.
3. The contact resistance between the electrode and the conductive jaw plate is large, which affects the power consumption and the life of the jaw plate.
If the above situations are compared, the consequences of too high volatile content are worse than too low volatile content.
Therefore, the volatilization of the electrode paste should be controlled within a certain range. See Section IV for specific indicators.
The lower the ash content in the electrode paste, the better, but limited to the source of raw materials, it is generally not higher than 5%. If the ash content is too high, the strength will be poor, the resistance will be large, the power consumption will be high, and the corresponding electrode consumption will also be high. Therefore, ash content is also one of the important indexes of electrode paste.
The above indicators are the factory standards of the manufacturer, but it is not enough to judge the quality of the electrode paste only by knowing the amount of ash and volatiles. It is necessary to identify whether the quality of the electrode paste meets the requirements. Only when the samples are sintered in the laboratory and pass the tests of mechanical strength, resistance coefficient, porosity, etc., can they meet the quality appraisal standard of electrode paste. However, due to this test method, the time from sampling to obtaining the test results is long and the speed is slow. Therefore, the manufacturing plant is only a reference index, but it is also an important index.